A display device includes a display panel including a non-folding area and a sliding area in order along a first direction, a display surface in the non-folding area and the sliding area, and the sliding area including an exposed area of the display surface closest to the non-folding area, the exposed area having a length along the first direction which is variable, a support member coupled to the display panel and movable together with the display panel, and a housing facing the support member with the display panel therebetween and defining an opening corresponding to the non-folding area. The housing is slidably extendable and contractable along the first direction, at the sliding area, the housing which is slidably contracted defines a first length of the exposed area, and the housing which is slidably extended defines a second length of the exposed area which is larger than the first length.